Python 2.7 quick reference

22.4. The exec statement: Execute Python source
code

To dynamically execute Python code, use a statement of
this form:

exec E0 [in E1 [, E2]]

Expression E0 specifies what to execute, and may be a
string containing Python source code, an open file, or
a code object.
If E1
is omitted, the code is executed in the local scope.
If E1
is given but E2
is not, E1
is a dictionary used to define the names in the global and local
scopes.
If E2
is given, E1
is a dictionary defining the global scope, and
E2
is a dictionary defining the local scope.